In a mobile communication system, in order to reduce as much as possible a feeder loss caused by a long cable between a base station under a tower and an antenna on the tower, it gradually becomes a trend to move the base station onto the tower. Corresponding product forms gradually appear as well, among which active antennas are commonly used. In an active antenna product, multi-channel antenna arrays are usually disposed corresponding to multi-channel signals. The antennal array of each channel works in parallel, and two processing units, namely, a transceiver channel unit and a Baseband Processing Unit (BPU), are disposed corresponding to the antenna array of each channel. The transceiver channel unit is an analog circuit including a lot of components, and most of the components are high-voltage, large-power, and high-current components, thereby causing the temperature of the transceiver channel unit to rise in work, which may further lead to a failure phenomenon; therefore, the reliability is low.
In view of the failure of a transceiver channel, the active antenna is usually equipped with an automatic compensation function, that is, to compensate the failed transceiver channel by adjusting a Digital Beam-forming (DBF) coefficient of the antenna array of each channel, thereby reducing the influence of the failed transceiver channel on the performance of the entire active antenna device. In the prior art, the automatic compensation function of the active antenna is usually implemented in a table lookup manner. In the table lookup compensation method, for each failure mode of the transceiver channel, a group of optimized DBF coefficients adaptive to the failure mode is calculated in advance. In addition, the calculated groups of the optimized DBF coefficients and the failure modes are correspondingly recorded in a DBF data table of the active antenna in advance. When a failure of some transceiver channel is detected, the active antenna device performs a query in the DBF data table according to a current failure mode, and writes the queried corresponding DBF coefficient into the transceiver channels that are not failed, thereby achieving an objective of failure compensation.
However, the table lookup compensation method has the following disadvantages: in an actual application, generally multiple antenna arrays are disposed in parallel corresponding to a single active antenna device, that is, multiple transceiver channels are disposed correspondingly; meanwhile, for each transceiver channel, actual failure modes further include different failure types (such as different downtilt angles). Therefore, in calculating the optimized DBF coefficient groups corresponding to the failure modes in advance, each failure combination should be fully considered, so as to avoid a phenomenon of failing to compensate a failure status. In this case, the corresponding workload is rather heavy. Especially, when the number of the antenna arrays forming the active antenna is great, the size of a failure mode DBF data table presents an exponential increase.